Electroresponsive device



Oct. 18,1927. P M CONRAD 6,233

ELECTRO RESPONS IVE DEVICE Filed Feb. 27. 1926 I i ll! maul H11 H !L llllllnn Inventor:

Paul M. Conrad His Attorr neij I Patented Oct. 18, 1927.

UNIT-ED STATES PATENT OFFICE.

PAUL M. CONRAD, OF- ALCOA TENNESSEE, ASSIGNOR TO GENERAL ELECTRIC "COIL PANY, A CORPORATION or NEW YORK.

' ELECTRORESPONSIVE DEVICE.

Application filed February 27 1926. Serial No. 91,211.

My invention relates gtQ ,electroresponsive devices .such for examplegas relays an l.. particularlytodevices of-this character. which are operated by 1 a: varying-pr alternating 5 electric current; .The object ofmyinvention is to secure in,devic es -of.- this character {a pick up and release at current values which are. not greatly different, other words-a close .range, operation,-. and to secureQalso an accelerating or snappy,- actionmof tl1 e. -'.,'n1ovable member .of the device as, distinguished from a uniform ordrifting i action. =A ,further object-is to secure .suclyan operation in efficientandpractical. apparatus -To accomplish these. ob ecta,-I provide means for impressing- ,upon. a movable member-a force which remains relatively constant throughout,v the movement of; said member during any-givemcondijtion of-' the actuating current; and I also provide ;meansfor impressing Eupon the anovable member another force which-increases or-decreases through out the movement-of saidwmovable member during .any given .condition' of the actuat- 2-5 ing currents- These two forces areigiven such absolute and relativevalues a s .is desired bysuitably proportioning or adjusting the dilferent elements .of the device. I

have alsov devised eflicientand practical apparatus for generating and applying-these forces. W

The following specification and the accompanying drawing disclose in detailone specific embodiment of my invention. -Referring to the drawing. Fig. 1 is a side view a of said relay; and Fig. 2 shows this relay associated with switches and circuits for changing the operation of' 'a -motor from forward to reverse and vice versa, with fluctuations of voltage in an alternating current line, and for maintaining. the motor at rest for a certain intermediate voltage.

Referring to Fig. 1. an actuatingelectro magnet 1 having a coil 1" and a core 2 acts upon a movable member 3 to causea movable contact 14 to engage a fixed contact. such as the contact 16, for certain conditions of the-current in the actuating coil 1' of the magnet 1. and to remain disengaged there from during .other conditions of the cur rent in this coil. The movable member 3 is ordinarily a lever. In the specificembodiment here illustrated it has three farms5, 6

and 7 radiating. from the fulcrum 4. A mass of conducting material 8 is 'mounted'on the movable member3 adjacent one endof th'e eoil l so as .to provide a .closed conducting path.-,forcurrents inducedtherein in rel sponse to variations .or alterations "of cur rentJin the coil 1. This mass ofconducting material 8 is here shown as a closed ri ng mounted on the arm 5 and loosely encircling an extending end of the core 2. In the relay shown, this closed conducting path 8 is made of non-magnetic material such as copper or aluminum. A mass 9 of magnetic material of low retentivitysuchas soft iron orsoft steel is also mounted on the movablemembei 3, and adjacent a pole of theelectromagnet 1. This mass of magnetic material 9'is here shown as a plate carried on' a bar 6 depending'from one end of the arm .6, so that the plate 9 is near the other end of the co re from that which isencircled by. theclosed conducting path 8. A contact 1 t iscarried by,the;=movable member 3 for cooperation with oneor more fixedfcontacts such asth'e contacts 15 and 16. In the construction showna varying or alternating currentin the coil 1 generates forces WhICh-aChTIPOII the ring 8 and plate 9 and tend to rotate the movable member 3 in a clockwise direction. This tendency is opposedby a force or forces which act upon the movable member 3 and tends to move it in a counterclockwise direction. A spring may be used to provide this opposing force such' as the spring 10 secured at one end tothe arm 7 and at its other end to the nut 11. The nut 11 as shown is adjustable in the sleeve 12 by means of the thumb screw 13. I

The device shown in Fig. 1 may be used either as a single or as a double contact relay. v'When used as a double contact relay, the spring 10 is adjusted to hold the movable contact 14 about half wavbetween the fixed contacts 15 and 16 when the strength of the current in the coil 1 is about half way between that strength at which the contact 14 is desired to engage the contact 15 and that strength at which the contact 14 is desired to engage the contact 16.v Asl long i as the current in the coil 1 remains at this strength, the lever 3 remains at rest and the contact 14 maintains its position apart from each of th'e contacts '15 and 16. .Hfthecu'rrent'in'the cciih'l tlc'reases n-lr'eh the Contact 14 is in its intermediate position, the repulsion of the 'ring 8 and the-attraction of the plate 9 decrease and thespring -1Q rotates the lever 3 until contact 14 engages contact 15. If the current in the coil mz hicrenses when the contact l t is in its intermediate position, the repulsion' o f me coil "8 at traction of the plate fli incrc so and the lever ai's rot'atHagai ist-th I s ii- Jr thfir'ii'ig 3 i'mtil tiiear' tset -14 iilgiigs fti'i' eoiitaet III 7 rite-savag with its if; t e pis e f9 :Were omitted, the difference bem qe i 'the piclc up v'ahie of the 'ciirreitt iii the coil '1. and its r lease "value 'i' 'vo'ul'd he very small 'iii'deetl 'tlie friction in the bearing a 'a'titlfthe'i ariatioiijinthe-teiisi'on 'of the spring 10 bein Considered negligible. But this ver close 'operation "though theoretically desirable would be attended by a sluggishness in the movement of the contac 14 which is undesirable. The ring 3 ould drift or more steadily to or from a contact engaging it- 1- tion -t'vhe'nei'erth'e current in the coil 1 le- 4 J w iarted slightly from itscritical value. here a'ii' accelerated hio'tion hot-h in piek n pand ii'pon the plate-9 at. 'theetitl'of ati ffioi'eme'fit thereof vguu'ld {be so much greater "the time n'ting at the Beginning nf thzit movement. as to ='m'a'q'u'n-e tvc dtfsi'detable change in the current in are mil-1% ab ii1'iti'ate' thereverse o'f'fihat movement. By'employing'boch the ring 's a'i'irltihe idlate' t), andprope -lypmpb'it'rdfliiig their r lative effect' venessaclose raiig' wpere'tibii mid 'u'ti' aeeeleratingiaetidn can be secured titftli'e sarne time. Where a 'very-los' riiiige qperaciun i's more important than 'a 'i 'eify snapp engagement dr disentl ie 'plate t) will be ma de smttll; or its ftli tzinc'e troin" the core ma'de =large,"('rr the ting 8"W'iI1= be-ina'd-e' i ery highly coritlhctin'g', 61'' (if laiger orosssecti'oh', or other means \tilllf employed, toflecrease tlie-iiitensity-6f the attraction-of ihe iilaie =9 relaiive to"'th'e repulsion ii the. rihg '8. Vic'e 'itsa Where a 'Sridppi'er motion 'isd esiretl and very close range is less important. the design tril l -b'e reversed. And in 'geliei a'l those skilled -in the art. will :f roportioii the -'rela- 'tive eff ct (if "the ring 8 ahd uit plate -9 "to eciire that prop'or'tioning of closeness 0t iange u'n'd snappiness of 'motion which they deem iiiost'dsl'talile in'th'e pai't-ichliir situa- -'t'ioii ili' \ih'ich they expect =thc relay -to 'he 'ii's'e'd. Y

*It tvill he'bii's'rved that the "lever 3 has impressed "thereon a 'force which "rn ii general way is pre m'tional to a resultant of the foiees e xefled by the electiomagiie t 1 "on the ring'8'and plate-9; and-that'the repulsion -of "the 'cdil'fla n'd a' tti'actiono'f themlate 9 the deem-magnet 1 vary with th'e'irttieiisity of tm altei n' tting 'ci'n'rent in the coil -1 ;-*and that "the 'movzlble member 3 moves in 'respoiis'cto -Viir-iaitidnfih the forces between the electro- 'm'a -giiet 1 and the closed conducting pat-hfi mid Iii'aSsPd-f magnetic mtl telllal 9, tor'eertain values of these forces.

What I claim as new and desire to secure by Letters Patent=of the United States is:

1. An electroresponsive device comprising an actuating coil, a' movable member, means for impressing on-said movable member a force which varies with the variation of the current in the actuating coil but does not vary substantially with the motion of the movable member, and means for impressing on said movable member another force which varies with the variation of the current in the actuating coil and which does substantially vary with the motion of said movable member.

2. An electroresponsive device comprising an actuating coil, a movable member, means for impressing on said movable member a force which varies with the variation of the current in the actuating coil but which does not vary substantially with the motion of the movable member, means for impressing on said movable member another force which varies with the variation of the current in the actuating coil and which does vary substantially with the motion of said movable member, and which is so directed as to aid the first mentioned force, and means whereby the motion of the movable member in response to said forces is opposed by a substantially constant force.

3. An alternating current electroresponsive device comprislng an actuating electromagnet, a mass of conducting material adj acent one end of said magnet, a mass of low retentivity magnetic material adjacent a pole of said magnet, a movable member and means for impressing on said movable member forces which are proportional to a resultant of the forces which are exerted by said electromagnet on said mass of conducting material and on said mass of magnetic material,

4. An alternatin current electroresponsi e device comprislng an actuating coil, a core projecting from said coil at one end, a closed path conductor loosely surrounding the projecting end of said core, a mass of low retentivity magnetic material adjacent a pole of said core, and a member which moves in response to variation in the forces acting between said coil, core, conductor and mass of magnetic material for certain values of these forces.

5. A close range alternating current electroresponsive device comprising an actuating coil, a fixed core in said coil said core project-ing at one end from said coil, a movable member, a closed path conductor carried by said movable member and surrounding said projecting end of said core, a mass of low retentivity magnetic material carried by said movable member adjacent the other end of said core, and means whereby a substantially constant force is exerted u on said movable member in opposition to tlie action of said coil and core upon said movable member, the action of said substantially constant force being equal to the action of said coil and core on said movable member current relay, comprising a lever, a closed path conductor of nonmagnetic material carried by one arm of said lever, a piece of soft iron or soft steel mounted on another arm of said lever, an actuating coil, a fixed core in said coil, said core extending beyond said coil at one end and through said closed path conductor, the other end of said core being adjacent said piece of iron or steel, a movable contact carried .by said lever, a fixed cont-act with which said movable contact cooperates, and a spring coacting with said lever to hold the movable contact spaced from the movable contact when the intensity of the current in the actuating coil is below a certain value.

7. An electroresponsive device comprisin a pivoted member having two arms, a close path of non-magnetic conducting material upon one arm, a mass of low retentivity magnetic material upon the other arm, an actuating coil located between said arms and having a. core, one end of which extends through the closed path of conducting material and the other end of which is near the mass of low retentivity magnetic material, a spring urging said pivoted member in a. direction opposite to the direction in which it is urged by the action of the coil and core.

8. An electroresponsive device comprising a pivoted member having two arms, a closed path of nonmagnetic conducting material upon one arm, a mass of low retentivity mag netic material upon the other arm, an actuating coil located between said arms and having a core, one end of which extends through the closed. path of conducting material and the other end of which is near the mass of low retentivity magnetic material, and a spring urging sald pivoted member in a direction opposite to the direct-ion in which it is urged by the action of the coil and core, the action of said spring being equal to the action of said core and coil for a certain predetermined intensity of alternating current in said coil.

9. An alternating current relay compris ing a movable member, an actuating coil having a. fixed core, a closed path of nonmagnetic conducting material mounted on said movable member and surrounding one end of said core, a plate of low retentivity magnetic material mounted on said movable member adjacent the other end of said core, a spring urging the movable member in a direction opposite to the direction in which it is urged by the action of the coil and core on the closed path of conducting material 'add the plate of ma netic-matei'ial, a mdv- 'dMe contact carried y 'saidrmoi able 'mem- "bezgwin-d t-w'o' fixed cpntactsfone-oh each side 'of "said m'dvable ddntact, the springllolding the movable conTtatspaced-from the fixed contacts for a given intensity of the current in the actuabing coilandv causi-ng or :permiton rises above saidgiven intensity.

In w tness whereof, I have hereunto sefl mfhand this 23rd dzyypf Februa y JQQG.

PAUL CONRAD.

Certificate of Correction.

Patent No. 1,646,233. Granted October 18, 1927, to PAUL M. CONRAD.

It is hereby certified that error appears in the printed specification of the abovennmbered patent requiring correction as follows: Page 1, line 59, for the word alterations read alternations; page 2, line 53, for the word variation read variations; same page, line 71, before the word accelerated insert the word (In; and that the said Letters Patent should be read with these corrections therein that. the same may conform to the record of the case in the Patent ()llice,

Signed and sealed this 6th day 0t December, A. D. 1927.

[SEAL] M. J. MOORE,

Acting Commissimwr of Patents: 

